/*
 * Created on 14-Oct-2004
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package org.gudy.azureus2.core3.peer.impl.transport;

/**
 * CURRENTLY UNUSED
 *
 */

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

public class PEPeerTransportDebugger {
    protected int piece_length;

    protected PEPeerTransportDebugger(PEPeerTransportProtocol transport) {
        piece_length = transport.getControl().getPieceLength(0);
    }

    public int write(SocketChannel chan, ByteBuffer buffer)

    throws IOException {
        int pos = buffer.position();

        int len = chan.write(buffer);

        if (len > 0) {

            buffer.position(pos);

            analyse(buffer, len);
        }

        return (len);
    }

    public long write(SocketChannel chan, ByteBuffer[] buffers, int array_offset, int array_length)

    throws IOException {
        int[] pos = new int[buffers.length];

        for (int i = array_offset; i < array_offset + array_length; i++) {

            pos[i] = buffers[i].position();
        }

        long len = chan.write(buffers, array_offset, array_length);

        for (int i = array_offset; i < array_offset + array_length; i++) {

            ByteBuffer buffer = buffers[i];

            int written = buffer.position() - pos[i];

            if (written > 0) {

                buffer.position(pos[i]);

                analyse(buffer, written);
            }
        }

        return (len);
    }

    protected static final int BT_READING_LENGTH_AND_TYPE = 1234567;

    protected int state = -1; // bt handshake
    protected byte[] data_read = new byte[68];
    protected int data_read_pos;

    protected void analyse(ByteBuffer buffer, int length) {
        byte[] data = new byte[length];

        buffer.get(data);

        for (int i = 0; i < data.length; i++) {

            if (data_read_pos == data_read.length) {

                if (state == BT_READING_LENGTH_AND_TYPE) {

                    ByteBuffer bb = ByteBuffer.wrap(data_read);

                    int len = bb.getInt();

                    state = bb.get();

                    // System.out.println( "Header: len = " + len + ", state = " + state );

                    if (len == 1) {

                        // messages with no body

                        // System.out.println( "msg:" + state );

                        state = BT_READING_LENGTH_AND_TYPE;

                        data_read = new byte[5];

                    } else {

                        data_read = new byte[len - 1];
                    }

                } else {

                    // messages with body

                    // System.out.println( "msg:" + state );

                    if (state == 7) { // bt piece

                        ByteBuffer bb = ByteBuffer.wrap(data_read);

                        int piece_number = bb.getInt();
                        int piece_offset = bb.getInt();

                        long overall_offset = ((long) piece_number) * piece_length + piece_offset;

                        while (bb.hasRemaining()) {

                            byte v = bb.get();

                            if ((byte) overall_offset != v) {

                                System.out.println("piece: write is bad at " + overall_offset + ": expected = " + (byte) overall_offset
                                        + ", actual = " + v);

                                break;
                            }

                            overall_offset++;
                        }
                    }

                    state = BT_READING_LENGTH_AND_TYPE;

                    data_read = new byte[5];
                }

                data_read_pos = 0;
            }

            data_read[data_read_pos++] = data[i];
        }
    }
}
